Small marble plaque indicates sacred spring. From Dr. Keefe's journal: "Then on to Akropolis -- esp. to see Asklepeion. They are trying to restore the original + have raised 3 doric columns to represent where Doric stone was. I found the 'ancient spring'. It is now an almost overgrown cistern surrounded by pigeons right back to back w/sheer wall of south side of Akropolis. You can peer down + still see water."